Battery hovering in the 50's and big fluctuations.

[v_traveller]

I'm still charging on 110V, even with 3 plug-ins (trick is to have them on separate breakers). At this point I'm switching to 220V only if I somehow score a free Level 2 EVSE. It helps that So Cal Edison has a time-of-use plan that offers 10 hours at the super-off-peak rate (10pm-8am). Apparently they lengthened the super-off-peak from 6 hours to 10 hours to accommodate customers with an EV that charge at 110V (which, according to SCE, is most of them).

So... you're definitely not alone in thinking that maybe you don't need 220v charging.

As far as 110V being better for the battery than 220V... from what I've read (from other folks that post here), it makes no difference to battery life, but that charging at 220V is more efficient than charging at 110V (10% or so?).

As far as being passed all the time to achieve 70+ miles/charge... I'm doing much more passing than being passed, even bumping into the speed limiter on almost a daily basis, and manage to get the equivalent of 80 miles/charge. So I'm thinking that now that you've figured out how to dramatically increase your efficiency, maybe you can figure out when/where you can apply full throttle for a second or two at a time that will have minimal effect on your range.

 

[EVA]

Congratulations. Glad you got to smooth driving!

Yeah, going really fast for a short time is a lot of fun and necessary. If you're driving on the highway, just draft a truck for a while to make up.

110V is fine. It just takes longer. You might find overnight won't get you a full charge at some point (meaning you drove a lot and had almost no charge left in the car when you parked it). 220V is way more efficient. The car seems to be happier. I could see it smile when it got the 220V EVSE. If you're using variable rate based on time of use - 220V is the only way to go. The FFE won't do delayed charging with 110V.

And if you happen to be in a cold climate, well 220V will heat up your car for you. 110V won't do as good a job.

 

[hybridbear]

In driving as coached by you guys in 4 days only I increased my GOM from about 52 miles to 72 miles for a full charge. Braking efficiency went from low 80's to high 90's and up to 100%. Thank you. That says there is hope for me. Do I like this driving? HECK NO! I'm not used to being passed by cars but it is the correct way and I can get back to my old habits when I drive the Hummer.

The improved braking scores will help a lot. If a range in the 50s is enough for your driving then feel free to fly down the road passing everyone and chirping the tires off the line. Braking gently and getting 100% or close to it on your stops will still improve your range. Keep an eye on your Lifetime Brake Score which should show on the left dash screen when you turn off the car. Maybe even reset it now so you can track how you do on braking going forward.

Do you all use 220V charging? I'm using 110V and I'm not finding a reason to put a thousand dollars to get a 220V. Also, am I right to think that slow 110V is better for the batteries?

I don't think there's any scientific evidence of one being better or worse for the batteries. There are a few advantages to L2:

• Thermal Management for the HVB doesn't necessarily work on L1
• Preconditioning is limited to cool the car on L1
• Preconditioning is non-existent to heat the car on L1
• Lower charging losses with L2 should mean less electricity consumption

It's not likely that an L2 charger will ever pay for itself in the amount of electricity you save unless you are able to use TOU rates with L2 and you are paying a higher $/kWh when using L1. The benefit of L2 is really convenience for preconditioning and being able to add about 20 miles for each hour of charging in range instead of only adding 4 miles for each hour of charging on L1.

If you're using variable rate based on time of use - 220V is the only way to go. The FFE won't do delayed charging with 110V.

The Value Charging worked for us on L1. In the month before we got our L2 EVSE we configured the car to show

• $$ from 12:00 - 1:00 am
• $ from 1:00 - 10:00 am
• $$$ from 10:00 am - 3:00 pm
• $$$$$ from 3:00 pm - 7:00 pm
• $$ from 7:00 pm - 12:00 am

The car would normally wait until 1:00 am to begin charging if it could finish before the next Go Time. If it couldn't it would usually start charging in the 7:00 pm - 12:00 am time slot. It would only charge enough during that time slot until it knew it could finish during the $ time. Once it accomplished that it would stop charging. If the battery was really depleted it would charge straight through, even charging in the $$$$$ time slot. Quite frequently when using L1 we'd arrive home needing about 10 hours of charging but there would only be 7 hours or so available from the 1:00 am start of the $ period before a Go Time around 8:00. This would cause the car to charge from about 7:00 - 10:00 pm and then it would stop and wait for 1:00 am to continue charging.

We don't have TOU rates, but our goal in charging in the middle of the night is to limit pollution. During the day our power grid is largely coal. However, our utility doesn't run any coal power plants overnight. During the night our electricity is all hydro, wind & nuclear. Thus, when we charge at night we are not using any electricity that adds CO2 to the atmosphere. Thus we try to always limit charging to nighttime.

 

[dmen]

... During the day our power grid is largely coal. However, our utility doesn't run any coal power plants overnight. During the night our electricity is all hydro, wind & nuclear. Thus, when we charge at night we are not using any electricity that adds CO2 to the atmosphere. Thus we try to always limit charging to nighttime.

At the risk of getting off topic, are you sure that's true? I understand that coal power plants (and nuclear and older nat gas) aren't generally turned off or even down much over the course of a day. This is why utilities have such low off peak electricity rates- supply can only be brought down a little, while demand goes way down. I read it takes 1-3 days to power up a coal plant after shutting down for maintenance. So I'd be surprised if your MN coal plants can be turned off every night and back on the next morning. Charging at night might be using a relatively lower portion of electricity from polluting sources but doubtful it's pollution-free.
Still at least 2 positive ways to look at night charging, though:
1. You're using energy that is otherwise essentially wasted, rather than adding to peak output from those coal plants during the day.
2. Nighttime coal burning releases NOx pollutants when they can't interact with sunlight and therefore don't cause ozone formation and don't contribute as much to smog.

And now back to the topic. Glad to see OP's range improved after a little time on the EV learning curve. Coming out of a terrible cold winter, my third with the FFE, I'm seeing my full range estimate climbing up from around 40 miles with cabin heating at 67F (range 65 with climate off)-- up to 90 miles yesterday! Along with the robins and the crocus shoots, I'll add my guess-o-meter to the list of signs that spring has arrived.

 

[hybridbear]

... During the day our power grid is largely coal. However, our utility doesn't run any coal power plants overnight. During the night our electricity is all hydro, wind & nuclear. Thus, when we charge at night we are not using any electricity that adds CO2 to the atmosphere. Thus we try to always limit charging to nighttime.

At the risk of getting off topic, are you sure that's true? I understand that coal power plants (and nuclear and older nat gas) aren't generally turned off or even down much over the course of a day. This is why utilities have such low off peak electricity rates- supply can only be brought down a little, while demand goes way down. I read it takes 1-3 days to power up a coal plant after shutting down for maintenance. So I'd be surprised if your MN coal plants can be turned off every night and back on the next morning. Charging at night might be using a relatively lower portion of electricity from polluting sources but doubtful it's pollution-free.
Still at least 2 positive ways to look at night charging, though:
1. You're using energy that is otherwise essentially wasted, rather than adding to peak output from those coal plants during the day.
2. Nighttime coal burning releases NOx pollutants when they can't interact with sunlight and therefore don't cause ozone formation and don't contribute as much to smog.

From a newspaper article about our local utility (Xcel Energy) and charging EVs at night.

Xcel’s off-peak power is carbon free anyway. Nighttime power comes from nuclear power plants, which run steadily, and wind farms, which often get the best breezes at night.

 

[Moolelo]

Just to address concerns over 120 vs 240 V charging. It will significantly reduce degradation of your battery to charge slower (120V outlet). This is a well known flaw of lithium ion, it crystallizes more and more each time you charge, reducing charge holding capacity of the battery over time. The faster you charge the quicker this happens.
http://www.greencarreports.com/news/1092854_why-lithium-ion-batteries-degrade-with-repeated-charging
From what I have seen in published science was ~2-5% over 5 years at 120V, ~5-10% at 240V, and as high as 15-20% using a level 3 charger. So the rule of thumb with engineers is you should use the slowest possible method you can get away with. Charge efficiency cost and waste is nothing compared to battery degradation. Same goes for cell phones, those new quick charge cell phones with non-user replaceable batteries are a gold mine. With something like 70% retained after 1 year of quick charging.

 

[michael]

Just to address concerns over 120 vs 240 V charging. It will significantly reduce degradation of your battery to charge slower (120V outlet). This is a well known flaw of lithium ion, it crystallizes more and more each time you charge, reducing charge holding capacity of the battery over time. The faster you charge the quicker this happens.
http://www.greencarreports.com/news/1092854_why-lithium-ion-batteries-degrade-with-repeated-charging
From what I have seen in published science was ~2-5% over 5 years at 120V, ~5-10% at 240V, and as high as 15-20% using a level 3 charger. So the rule of thumb with engineers is you should use the slowest possible method you can get away with. Charge efficiency cost and waste is nothing compared to battery degradation. Same goes for cell phones, those new quick charge cell phones with non-user replaceable batteries are a gold mine. With something like 70% retained after 1 year of quick charging.

I'm sorry, but I am quite confident this is not correct. Based on everything I have read, 6 kW class charging is not more detrimental to to battery life.

120 V charging can be worse for the battery because the battery stays at a higher average state of charge and a higher temperature compared to level 2 charging "just in time". The cited paper on greencarreports does not say that level 1 charging is better for the battery, and in fact I am unaware of any published report that says this is the case.

This is particularly true for the FFE because the TMS is ineffective at level 1.

Look at page 24 of this presentation:

http://www.nrel.gov/docs/fy14osti/62813.pdf

By their analysis, the worst thing is "charge upon plug in" because the battery stays hot and fully charged a long time (all night, for example). Slow charge is better, but best for battery life is "late 6.6 kW charge"


This recent paper

http://avt.inl.gov/pdf/energystorage/FastChargeEffects.pdf

indicates that even DC fast charging has a only a small negative effect on battery charging. The NREL paper above agrees...it indicates that late fast charging is substantially equivalent to slow charging in terms of battery degradation.


Can you cite a paper showing level 1 charging is better for battery life?

 

[pjam3]

It also depends on where you live in SD. I get about 70 miles on average, much less other times, but there are tons of small inclines in SD that kills your range. I've had discussions with others in the area who drive Teslas, Leafs, i3s and so on and it's the same scenario. If you have any hill or inclines, the electric cars don't do well at all. And if you have an incline + freeway speeds, your'e probably screwed. But there are charging parking lots and stations at places like Fashion Island mall, near downtown Main St Temecula and so on.

I pretty much know that going from where I live to the airport in SD, I need a full charge, can't exactly go that fast, can't take detours or I will wind up screwed. You might not have these issues, who knows, or you might and not even realize it. Most of my inclines aren't that big, but they are draining and there is no possible way to get up those hills without pushing on the gas. I've tried to do it in the past and the car pretty much will wind up going backwards and if you're on a freeway, you'd be the person causing an accident.

My kids school is not even 1.5 miles away, but i will leave with say 70 miles, and get to his school with less than 60. And coming back home doesn't get me back to even. So when you have inclines that are just slow and steady, but large enough, a 3 mile trip seems to drain about 10-15 miles of energy. And the "guess" is nice, but the reality is I've done this enough to know that a 3 mile round trip pretty much drains the car over about 7 days. It is just a terrible car if you have any kind of inclines and the declines are not on the same level. If I started with 70, went down to 69, but wound up with say 66 or 67, it would be no big deal. But I'll start with 70, go down to 55, go back up to 60, but it's a 3 mile round trip and I just lost 7 miles. That's the reality I've come to accept with the FFE and talking to many others with various electric cars, it seems to be a pain point. It also makes going to many places in SD a pain because people don't realize there are quite a few hills and inclines. If you drive up to Temecula or Fallbrook or Julian you start to realize how terrible these cars are driving up hills. But avoid that, you should be fine.

`

 

[brogult]

Based on everything I have read, 6 kW class charging is not more detrimental to to battery life.

If it were, the 50 kW or so of max regen would really be a problem. Everything I know boils down to keeping the bulk charge current under 0.8C and the temperature below 86F. And that is for old "conventional" chemistry batteries.

This is particularly true for the FFE because the TMS is ineffective at level 1.

Since you have a scan tool and I don't, have you ever measured the battery temperatures under those conditions? I've only ever observed my TMS on at one time while charging (on a warm day) and it appeared to only be circulating coolant. I haven't owned it through a summer yet, so I'll keep watching. I'd be curious to see how warm they actually get above ambient at various charge levels.

 

[michael]

The TMS appears to limit temperature to 98 F. Battery temperature climbs until it reaches that temperature and then stabilizes. You can hear the TMS cut in at that time. It appears to make no effort to limit temperatures below that point, although coolant does circulate to equalize temperatures through the pack.

I confess that I don't have first hand knowledge that the TMS is ineffective at level 1 but have relied on statements I've seen here. In reality, I've never once charged at 110 V in 36,000 miles.

 

[brogult]

Are you saying that charging always, or usually, warms the battery up to 98F? Or is it just when it is pretty warm to begin with?

 

[WattsUp]

... a 3 mile trip seems to drain about 10-15 miles of energy.

No. The range estimate doesn't indicate "energy". Any high school science student knows that energy is not measured in miles. Thinking of the range estimate as any kind of "energy meter" is nonsensical, and represents a fundamental misconception of the information it conveys.

Just because you started your trip with a 70-mile estimate and ended with a 60-mile estimate doesn't mean that the trip has somehow drained away "10 miles of energy". That is simply the wrong way to think about the range estimator. The same outcome could occur with a 5 mile trip or a 25 mile trip, depending on how each was driven.

Given exactly the same amount of energy in the battery, the range estimate can vary wildly depending on past driving patterns. But, it is only the estimate that is different, not the relative amount of energy in the battery. An especially troublesome scenario is when you drive up and down hills, and the energy consumption rate is changing drastically over very short periods of time (going uphill one moment, consuming heavily, going downhill the next, using much less energy and possibly even regenerating). These quick variations in the rate of consumption can lead to equally wide variations in the currently estimated range.

And just because the range estimate can be drastically affected by going uphill (or downhill for that matter) does not indicate that the FFE, or EVs in general, are "very bad with hills". More energy is required for any car to drive up a hill versus driving down it. The range estimate for a tank of gasoline also changes drastically if one starts driving up a lot of hills in an ICE car. This isn't a surprise to anybody.

Anyway, hills or other terrain, if you want to see how much energy (in actual units of energy) was used for a given trip, the FFE has other displays that are actually intended for that purpose:

1) The trip meter. Switch it to advanced mode, and reset it before starting a trip. It will count the total kWh used (and even counts backwards to reflect any energy gained from regen). This measurement is completely independent of the range estimate, and is instead entirely reflective of the actual energy used. By all accounts, the display of kWh used is quite accurate.

2) The percent state-of-charge display (shown on the energy screen on the MFT display). Simply make note of the percent SOC at both the start and end of a given trip and you will have a good understanding of how much energy that trip requires (that is, proportionally, relative to a full charge). Again, this measurement is completely independent of any range estimate and, despite a slight non-linearity in the higher percentages reported by some, it also very accurate.

 

[jeffand]

Heat is what ages the battery faster. The Nissan Leaf does not have a liquid cooling system for its battery. So in hot climates the battery ages faster. The faster the battery is charged the hotter it will get. So an effective cooling system is important in reducing the heat. So if you have an effective battery cooling system, level 2 charging should not be an issue. This is why most level 3 charging is limited to 80% by default.

 

[michael]

Are you saying that charging always, or usually, warms the battery up to 98F? Or is it just when it is pretty warm to begin with?

It depends on the temperature of the battery when you start charging, and to a lesser extent on the ambient temperature.

As an example, suppose I would arrive at work in the morning with the battery at maybe 30% and 85 degrees F with an ambient temperature of 70 F and then I would plug it in to charge. This after an hour of driving.

By 11 AM, it would be charged to maybe 75% or 80%, the ambient temperature maybe 75, and the battery would have reached 98 but no higher unless it's really hot out. At noon, it would be fully charged, and the temperature 98 or perhaps a few degrees higher. Once charging ended, the TMS would bring it back down to 98 and then stop cooling.

Depending on the ambient temperature, it might cool down a few degrees in the course of the afternoon, or it might not if very hot out.

On the other hand, if I would start charging in the early morning with the battery starting at 60 F, it might never reach 98. Depends on how much charge it takes and starting temp.

I know this is vague, but does it give the idea?

Basically, the battery will heat at whatever rate the charging and ambient cause until it reaches 98, and then it will go little if any higher.

Let me know if I helped or made more confusing.


Also...3 kW charging does not seem to result in significantly lower temperatures than 6 kW charging (maybe a little, not enough to be obvious) . It takes twice as long to heat up, yes, but reaches pretty much the same temperatures. I was puzzled at first, but now I conclude that the battery is insulated very, very well, so the temperature rise is based on the added energy and not greatly affected by how fast the energy is added.

In other words, if you need to put in 20 kWh to charge the battery by 16 kWh, there is 4 kWh converted to heat and the battery temp raises by approximately the same amount.

 

[pjam3]

I do understand the estimate, miles, and energy are not one in the same, but the reality is I can measure how far I can go in miles and going back and forth to my kids school is about 3 miles roundtrip, if that. And to me how far I can go is the best way to measure anything as I've spent the past year and a half testing the limits of the car. I know that driving from my place to Newport Beach is about 55 miles and I've died going that far. I know going from my house to Temecula and back, with those hills, I wouldn't make it back home.

So after a year and a half, the reality is the car gets about 60 miles most weeks for me and nothing more. And I never really take freeways. Hills do make electric cars a pain because they are limited in range. Yes a ICE will eat gas and kill a transmission or clutch if you go up and up and over and over again, but I still can go from my house to LAX and back without worrying about getting gas. Whereas I can't even make it halfway in the FFE.

So estimate or not, going to certain places does drain far more energy and you lose range compared to other areas. And for a car that gets about 70-80 miles at best of range, having hills around will be a huge issue for the FFE, Leaf, etc.